Wind power generator is an important device for transforming mechanical energy into electric energy. In a wind power generator, there exist electromagnetic forces of multiple different frequencies such as fundamental wave, harmonic frequencies, a cogging frequency and frequency multiplication thereof, etc. In addition, the stator and rotor of the wind power generator have complicated mechanical structure modal. When a force wave order and a frequency of electromagnetic force of the generator correspond to a vibration mode order and a frequency of a stator and rotor mechanical structural modal of the generator respectively, resonance occurs, which results in outstanding vibration and noise problems. By decreasing a magnetic load of the generator, i.e., by decreasing electromagnetic force on stator and rotor of the generator, vibration amplitude of the stator and rotor of the generator is decreased, thereby suppressing vibration and noise of the generator, and implementing an objective of vibration damping and noise reduction.
In an existing technology, the magnetic load of the generator is decreased by changing a mechanical structure and electromagnetic design thereof, such as by increasing the length of an air gap of the generator, optimizing the shape of magnetic pole, inclining the slot (that is, obliquely putting the coils against the stator and rotor of the generator), or inclining a magnetic pole (that is, inclining the magnetic pole) and so on.
With the change of the mechanical structure and the electromagnetic design of the generator, performances thereof, such as power density and force-energy index, are decreased, and the complexity of manufacturing processes and the cost of the generator are increased.